Using the Stereo 3D module effectively starts with choosing a depth perception method that is most comfortable or convenient.
By default, the Side-by-side Right/Left (Cross) Mode is used, which allows for seeing 3D using the cross-viewing technique. If you are more comfortable with the parallel-viewing technique, you may select Side-by-side Left/Right (Parallel). The benefits of the two aforementioned techniques is that they do not require any visual aids, while keeping coloring intact. The downside of these methods, is that the entire image must fit on half of the screen. E.g. zooming in breaks the 3D effect.
If you have a pair of red/cyan filter glasses, you may wish to use one of the three anaglyph Modes. The two monochromatic anaglyph modes render anaglyphs for printing and viewing on a screen. The screen-specific anaglyph will exhibit reduced cross-talk (aka "ghosting") in most cases. An "optimized" Color mode is also available, which retains some coloring. Visual spectrum astrophotography tends to contain few colors that are retained in this way, however narrowband composites can benefit. Finally, a Depth Map mode is available to inspect (or save) the z-axis depth information that was generated by the current model.
The depth information generated by the Stereo 3D module is entirely synthetic and should not be ascribed any scientific accuracy. However, the modelling performed by the module is based on a number of assumptions that tend to hold true for many Deep Space Objects and can hence be used for making educated guesses about objects. Fundamentally, these assumptions are;
Depth information is created between two planes; the near plane (closest to the viewer) and the far plane (furthest away from the viewer). The distance between the two planes is governed by the 'Depth' parameter.
The 'Protrude' parameter governs the location of the near and far planes with respect to distance from the viewer. At 50% protrusion, half the scene will be going into the screen (or print), while the other half will appear to 'jut out' of the screen (or print). At 100% protrusion, the entire scene will appear to float in front of the screen (or print). At 0% protrusion the entire scene will appear to be inside the screen (or print).
The 'Luma to Volume' parameter controls whether large bright or dark structures should be given volume. Objects that primarily stand out against a bright background (for example, the iconic Hubble 'Pillars of Creation' image) benefit from a shadow dominant setting. Conversely, objects that stand out against a dark background (for example M20) benefit from a highlight dominant setting.
The 'Simple L to Depth' parameter naively maps a measure of brightness directly to depth information. This a somewhat crude tool and using the 'Luma to Volume' parameter is often sufficient.
The 'Highlight Embedding' parameter controls how much bright highlights should be embedded within larger structures and context. Bright objects such as energetic stars are often the cause of the visible emissions around them. Given they radiate in all directions, embedding them within these emission areas is the most logical course of action.
The 'Structure Embedding' parameter controls how small-scale structures should behave in the presence of larger scale structures. At low values for this parameter, they tend to float in front of the larger scale structures. At higher values, smaller scale structures tend to intersect larger scale structures more often.
The 'Min. Structure Size' parameter controls the smallest detail size the module may use to construct a model. Smaller values generate models suitable for widefields with small scale detail. Larger values may yield more plausible results for narrowfields with many larger scale structures. Please note that larger values may cause the model to take longer to compute.
The 'Intricacy' parameter controls how much smaller scale detail should prevail over larger scale detail. Higher values will yield models that show more fine, small scale changes in undulation and depth change. Lower values leave more of the depth changes to the larger scale structures.
The 'Depth Non-linearity' parameter controls how matter is distributed across the depth field. Values higher than 1.0 progressively skew detail distribution towards the near plane. Values lower than 1.0 progressively skew detail distribution towards the far plane.
